During Greenspan’s refinancing boom of 2000–2003, it wasn’t just the GSEs that were busy. The huge surge in issuance meant that there was plenty of unconventional, “nonconforming” business to go around too. But the decisive thing was what happened in early 2004 when interest rates had reached rock bottom, the refinancing boom had run its course and the GSEs were stopped in their tracks. With the pipeline ready and waiting, it was at this point that the private mortgage industry took over. Leaving behind the GSE-centered model of the 1990s, they deprioritized conforming
